A force sensor improves trainee technique for rigid endoscopy.

OBJECTIVE: Developing skills in rigid endoscopy poses challenges to the surgical trainee. This study investigates whether a modified manikin can improve the technical skill of junior operators by providing direct quantitative feedback. METHODS: A force-sensing pad was incorporated into the oral cavity of a life support manikin. Junior trainees and senior otolaryngologists were invited to perform rigid endoscopy and received real-time feedback from the force sensor during the procedure. RESULTS: There was a significant inverse correlation between operator seniority and the weight applied to the oral cavity (p < 0.0001). All junior trainee operators applied less weight after five attempts (346 ± 90.95 g) compared to their first attempt (464 ± 85.79 g). This gave a statistically significant decrease of 118 g (standard deviation = 107.27 g, p = 0.007) when quantitative feedback was provided to learning operators. CONCLUSION: This low-cost, simple model allows trainees to rehearse a high-risk procedure in a safe environment and adjust their operative technique.

Stereotactic Radiosurgery and Radiotherapy for Vestibular Schwannoma in NF2-Related Schwannomatosis.

OBJECTIVES: To determine the long-term control rates and hearing outcomes for growing vestibular schwannoma in NF2-related schwannomatosis (NF2) treated with stereotactic radiosurgery (SRS) and fractionated radiotherapy (FRT). METHODS: Retrospective review of all patients treated with SRS/FRT between 1986 and2021 from a tertiary NF2 unit. Overall tumor control was defined as: (1) growth control (growth failure was defined as growth in any dimension of 3 millimetres or more from baseline post-SRS/FRT), and (2) treatment control (no need for further intervention). Loss of serviceable hearing was defined as a drop in speech discrimination score below 50% after SRS/FRT. RESULTS: There were 81 cases, with a mean duration of follow-up of 125 months. Overall control rate was 72% (58/81), with 80% (65/81) growth control and 74% (60/81) treatment control. There was a 5-year actuarial survival of 77% and 10-year survival of 71%. Forty-three percent (30/69) of cases did not have serviceable hearing at baseline. Of those remaining, 49% (19/39) preserved serviceable hearing during follow-up at a mean of 106 months. Actuarial survival for preservation of serviceable hearing at 5 and 10 years was 69% and 53%. There were poorer outcomes with increasing genetic severity, and with baseline tumor size >3 cm. No cases of SRS/FRT-related malignancy were identified at a mean follow-up of 10 years. CONCLUSION: Stereotactic radiosurgery/fractionated radiotherapy are an effective option to treat growing vestibular schwannoma in patients with NF2 with the potential for hearing preservation in a proportion of patients. LEVEL OF EVIDENCE: 4-Case Series Laryngoscope, 134:2364-2371, 2024.

Updated protocol for genetic testing, screening and clinical management of individuals at risk of NF2-related schwannomatosis.

Genetic testing and management of individuals at risk for NF2-related schwannomatosis is complicated by the high rate of mosaicism resulting in a milder, later onset, more asymmetrical disease and the phenotypic overlap with the related schwannomatosis conditions. This updated protocol has been devised for the English NF2-related schwannomatosis service. It provides those affected with mosaic NF2-related schwannomatosis estimated risks of having an affected child; and management guidelines both for individuals at risk of NF2-related schwannomatosis, or with potential disease, due to having features that fall short of consensus diagnostic criteria. Risks of mosaicism and inferred transmission risks were derived from genetic testing of over 1000 individuals through the Manchester NF2 genetic testing service. This updated protocol, reflects the lower transmission risks now inferred in mosaic NF2-related schwannomatosis, informed by the greater sensitivity of Next Generation Sequencing in detecting low levels of mosaicism in blood, along with improved ability to analyse tumour DNA. Screening for features of NF2-related schwannomatosis is proposed until the risk of having the condition falls below a pragmatic threshold of 1%. Using these revised transmission figures, this threshold can now be reached at a younger age in many of those at risk, with earlier reassurance and discharge.

Structural Abnormalities of the Central Retina in Neurofibromatosis Type 2.

INTRODUCTION: This case-control study seeks to systematically characterize the central retinal findings in a large cohort of patients with neurofibromatosis type 2 (NF2) using spectral domain optical coherence tomography (SD-OCT) as well as the examination of the potential use of this technique as a diagnostic tool in NF2. METHODS: Fifty-four patients with an NF2 diagnosis seen in a quaternary national service were age- and gender-matched to 55 controls from the normal population. Two masked assessors categorized SD-OCT images using predefined abnormalities: retinal tufts, epiretinal membrane (ERM) appearance, retinal hamartoma, and foveal contour. Specificity, sensitivity, and positive and negative predictive values were calculated for each retinal abnormality. Trends of retinal abnormalities with NF2 genetic severity groups (1. tissue mosaic; 2A. mild classic; 2B. moderate classic; and 3. severe) were investigated. RESULTS: We found retinal abnormalities in 26 patients with NF2 (48%) and 2 control patients (4%); retinal tufts were the most common abnormality therein (43%) and were not seen in controls. The specificity and sensitivity of the graded abnormalities on OCT scans in NF2 were 96% and 48%, respectively, with a positive predictive value of 93%. In our cohort, retinal tufts had a specificity of 100%, a sensitivity of 43%, and a positive predictive value of 100%. Retinal hamartomas were seen only in NF2 patients (35% sensitivity and 100% specificity). ERMs had 96% specificity and 13% sensitivity. The proportion of patients with retinal abnormalities increased statistically significantly with NF2 genetic severity; all patients within the 3. severe genetic severity had an abnormal SD-OCT. DISCUSSION/CONCLUSION: We present a systematic study of central retinal abnormalities in an NF2 population as seen on SD-OCT imaging. Our results show a high frequency of retinal abnormalities that are readily detected by SD-OCT imaging. The presence of retinal tufts may be a novel marker of NF2 with both high specificity and a positive predictive value for NF2, compared to other well-known ocular features of NF2, and may have a place in the NF2 diagnostic criteria.

Trends in phenotype in the English paediatric neurofibromatosis type 2 cohort stratified by genetic severity.

Childhood onset neurofibromatosis type 2 can be severe and genotype dependent. We present a retrospective phenotypic analysis of all ascertained children in England 1.0). Focal cortical dysplasia occurred in 26% group 3 and 4% 2A. A total of 48% of group 3 underwent ≥1 major intervention (intracranial/spinal surgery/Bevacizumab/radiotherapy) compared to 35% of 2A; with 23% group 3 undergoing spinal surgery (schwannoma/ependymoma/meningioma resection) compared to 4% of 2A. Mean age starting Bevacizumab was 12.7 in group 3 and 14.9 years in 2A. In conclusion, group 3 phenotype manifests earlier with greater tumour load, poorer visual outcomes and more intervention.

First report of the efficacy of vestibular rehabilitation in improving function in patients with Neurofibromatosis type 2: an observational cohort study in a clinical setting.

PURPOSE: Patients with Neurofibromatosis type 2 often experience debilitating neuro-otological problems which affect their mobility and balance. This study examined the efficacy of a personalised program of vestibular rehabilitation for patients with Neurofibromatosis type 2. MATERIALS AND METHODS: An observational cohort study analysing routinely collected data for 21 patients in a highly specialised Neurofibromatosis type 2 service. Vestibular rehabilitation comprised an initial one-hour assessment followed by a patient-specific exercise program reviewed in person and by email consultations. Patients were subsequently followed-up at 9 months. The vestibular rehabilitation efficacy was assessed using the Dynamic Gait Index score. RESULTS: Nineteen of 21 patients were assessed as impaired and at risk of falls pre-rehabilitation (Dynamic Gait Index <19/24), of which 79% showed clinical improvement post-rehabilitation. There was a significant improvement in the Dynamic Gait Index scores pre-rehabilitation to post-rehabilitation (p < 0.001) and outcomes were subsequently maintained at the 9-month follow-up assessment. Whilst the pre-rehabilitation Dynamic Gait Index scores of patients with more severe genotype were lower compared to other patients, the beneficial effect of vestibular rehabilitation was similar amongst genetic severity groups. CONCLUSIONS: Personalised vestibular rehabilitation significantly improves function in Neurofibromatosis type 2, sustaining benefits for 9 months, irrespective of patients' age or genetic severity. Implications for rehabilitation Patients with Neurofibromatosis type 2 experience debilitating neuro-otological problems which affect their mobility and balance. A patient-tailored program of vestibular rehabilitation was offered in a highly specialised clinic for six months with a follow-up assessment at 9 months post-treatment. All patients improved from baseline, with 79% of them achieving clinically significant improvement in function and with statistically significant benefits sustained for 9 months. The beneficial effect of vestibular rehabilitation was similar for all patients, regardless of age or genetic severity, suggesting vestibular rehabilitation could be incorporated in routine clinical care in Neurofibromatosis type 2 clinics internationally.

Neurofibromatosis Type 2-Related Eye Disease Correlated With Genetic Severity Type.

OBJECTIVE: Neurofibromatosis type 2 (NF2) is an uncommon but well-recognized disorder characterized by multiple schwannomas and meningiomas. Adults typically present with hearing loss and balance disturbance, and children with ocular, dermatological, and neurological signs. Clinical diagnosis is confirmed by neuroimaging and genetic testing. Although ophthalmic features are present in patients with NF2, there are no reports correlating genetic severity subtypes with ophthalmic involvement. METHODS: We retrospectively reviewed longitudinal ophthalmological data of 83 patients with NF2, with known genetic severity subtype, to determine visual function over time. We created a scoring system (Oxford NF2 Ophthalmic Score [ONOS]) to quantify visually debilitating pathology. RESULTS: The prevalence of optic atrophy, combined hamartomas, cataract, and epiretinal membranes significantly increased with genetic severity. Median age of survival to visual acuity worse than 1.0 logarithm of minimum angle of resolution in one eye significantly decreased with genetic severity and was 38 years in the genetically severe group, 49 years in moderate classics, 64 years in mild classics, and 84 years in the tissue mosaics. In the genetically severe, the visually damaging pathologies were largely untreatable. The ONOS correlated with genetic severity longitudinally and cross-sectionally. CONCLUSIONS: Mutations associated with severe systemic disease result in greater visual morbidity at an earlier age. Those with tissue mosaicism are unlikely to have visually debilitating pathology secondary to NF2. Potentially treatable sources of damage to vision, however, affect all groups and must be identified early and treated effectively to retain useful vision throughout life.

Progression of hearing loss in neurofibromatosis type 2 according to genetic severity.

OBJECTIVES/HYPOTHESIS: This study set out to describe the progression of hearing loss in patients with neurofibromatosis type 2 (NF2), treated in a quaternary multidisciplinary clinic. It also aimed to compare hearing loss across patients grouped according to a known genetic severity score to explore its utility for prognostication. STUDY DESIGN: Retrospective cohort study. METHODS: We conducted a study of 147 patients with confirmed NF2 diagnosis for a mean observational period of 10 years. Pure-tone average (PTA), optimum discriminations scores (ODS), and genotype data were collected. Patients were classified according to hearing class (American Academy of Otolaryngology), their candidacy for auditory implantation (UK National NF2 consensus) and grouped by genetic severity as: 1 = tissue mosaic, 2A = mild classic, 2B = moderate classic, and 3 = severe. Survival analysis investigated the effect of genetic severity on the age of loss of serviceable hearing. RESULTS: Genetic severity was a significant predictor of hearing outcomes such as ODS, hearing classification, and maximum annual PTA deterioration. Although the overall median age of loss of serviceable hearing was 78 years, there was significant variation according to the genetic severity; the median for severe patients was 32 years compared to a median of 80 for tissue mosaic patients. CONCLUSIONS: This is the first description of long-term hearing outcomes in a clinical setting across a large heterogeneous cohort of patients with NF2. The results highlight the potential importance and benefit of considering the genetic severity score of patients when undertaking treatment decisions, as well as planning future natural history studies. LEVEL OF EVIDENCE: 2c Laryngoscope, 129:974-980, 2019.

Genetic Severity Score predicts clinical phenotype in NF2.

​BACKGROUND: The clinical severity of disease in neurofibromatosis type 2 (NF2) is variable. Patients affected with a constitutional truncating NF2 mutation have severe disease, while missense mutations or mosaic mutations present with a milder attenuated phenotype. Genotype-derived natural history data are important to inform discussions on prognosis and management. METHODS: We have assessed NF2 clinical phenotype in 142 patients in relation to the UK NF2 Genetic Severity Score to validate its use as a clinical and research tool. RESULTS: The Genetic Severity Score showed significant correlations across 10 measures, including mean age at diagnosis, proportion of patients with bilateral vestibular schwannomas, presence of intracranial meningioma, spinal meningioma and spinal schwannoma, NF2 eye features, hearing grade, age at first radiotherapy, age at first surgery and age starting bevacizumab. In addition there was moderate but significant correlation with age at loss of useful hearing, and weak but significant correlations for mean age at death, quality of life, last optimum Speech Discrimination Score and total number of major interventions. Patients with severe disease presented at a younger age had a higher disease burden and greater requirement of intervention than patients with mild and moderate disease. CONCLUSIONS: This study validates the UK NF2 Genetic Severity Score to stratify patients with NF2 for both clinical use and natural history studies.

Aspirations to become an anaesthetist: longitudinal study of historical trends and trajectories of UK-qualified doctors' early career choices and of factors that have influenced their choices.

BACKGROUND: It is important to inform medical educators and workforce planners in Anaesthesia about early career choices for the specialty, factors that influence them and to elucidate how recent choices of men and women doctors relate to the overall historical trends in the specialty's popularity. METHODS: We analysed longitudinal data on career choice, based on self-completed questionnaires, from national year-of-qualification cohorts of UK-trained doctors from 1974 to 2012 surveyed one, three and 5 years post-qualification. Career destination data 10 years post-qualification were used for qualifiers between 1993 and 2002, to investigate the association between early choice and later destinations. RESULTS: In years 1, 3 and 5 post-qualification, respectively, 59.9% (37,385), 64.6% (31,473), and 67.2% (24,971) of contactable doctors responded. There was an overall increase, from the early to the later cohorts, in the percentage of medical graduates who wished to enter anaesthesia: for instance year 1 choices rose from 4.6 to 9.4%, comparing the 1974 and 2012 cohorts. Men were more likely than women to express an early preference for a career in anaesthesia: for example, at year 3 after qualification anaesthesia was the choice of 10.1% of men and 7.9% of women. There was a striking increase in the certainty with which women chose anaesthesia as their future career specialty in recent compared to earlier cohorts, not reflected in any trends observed in men choosing anaesthesia. Sixty percent of doctors who were anaesthetists, 10 years after qualifying, had specified anaesthesia as their preferred specialty when surveyed in year 1, 80% in year 3, and 92% in year 5. Doctors working as anaesthetists were less likely than those working in other hospital specialties to have specified, as strong influences on specialty choice, 'experience of the subject' as students, 'inclinations before medical school', and 'what I really want to do'. Men anaesthetists were more influenced in their specialty choice than men in other hospital specialties by 'wanting a career with acceptable hours'; the corresponding difference among women was not significant. CONCLUSIONS: We suggest a focus on inspirational teaching of anaesthesia in medical school and on greater exposure to the specialty in the foundation programme. Factors which may discourage women from entering anaesthesia should be explored and addressed.

Sidekick for Membrane Simulations: Automated Ensemble Molecular Dynamics Simulations of Transmembrane Helices.

The interactions of transmembrane (TM) α-helices with the phospholipid membrane and with one another are central to understanding the structure and stability of integral membrane proteins. These interactions may be analyzed via coarse grained molecular dynamics (CGMD) simulations. To obtain statistically meaningful analysis of TM helix interactions, large (N ca. 100) ensembles of CGMD simulations are needed. To facilitate the running and analysis of such ensembles of simulations, we have developed Sidekick, an automated pipeline software for performing high throughput CGMD simulations of α-helical peptides in lipid bilayer membranes. Through an end-to-end approach, which takes as input a helix sequence and outputs analytical metrics derived from CGMD simulations, we are able to predict the orientation and likelihood of insertion into a lipid bilayer of a given helix of a family of helix sequences. We illustrate this software via analyses of insertion into a membrane of short hydrophobic TM helices containing a single cationic arginine residue positioned at different positions along the length of the helix. From analyses of these ensembles of simulations, we estimate apparent energy barriers to insertion which are comparable to experimentally determined values. In a second application, we use CGMD simulations to examine the self-assembly of dimers of TM helices from the ErbB1 receptor tyrosine kinase and analyze the numbers of simulation repeats necessary to obtain convergence of simple descriptors of the mode of packing of the two helices within a dimer. Our approach offers a proof-of-principle platform for the further employment of automation in large ensemble CGMD simulations of membrane proteins.